Substituted pyrimidine derivatives useful in the treatment of autoimmune diseases

ABSTRACT

Disclosed are novel compounds useful in the treatment of multiple sclerosis and other autoimmune diseases. The present invention describes compounds of formula (I) 
     
       
         
         
             
             
         
       
     
     wherein:
 
R 1  is selected from H and CH 3  
 
R 2  is selected from H, C 4 H 9  alkyl, C 6 H 13  alkyl and C 3 H 6 -phenyl, said phenyl optionally substituted by OH or OCH 3 , (1R,2S,5S)-5-methylcyclopent-3-ene-1,2-diol
 
X is O or S
 
Y is C, N or S.

TECHNICAL FIELD

The invention relates to novel substituted pyrimidine derivatives usefulin the treatment of autoimmune diseases, particularly multiplesclerosis. This invention also relates to the use of such compounds inthe treatment of autoimmune diseases, particularly multiple sclerosisand to pharmaceutical compositions containing such compounds.

BACKGROUND ART

Multiple sclerosis (MS) is a debilitating disease of the central nervoussystem (CNS) in which the body's own immune system attacks the whitematter of the brain and spinal cord. This triggers inflammation-induceddamage to the CNS protective myelin layer causing demyelination. Loss ofmyelin exposes neurons to further attack leading to formation ofmultiple sclerotic lesions. This damage disrupts the ability of parts ofthe nervous system to communicate, resulting in a wide range of problemsincluding fatigue, blurred vision, cognitive impairment, and spasticity.Many patients suffer from the development of irreversible motordisability. Long term prognosis is poor, within 15 years of diseaseonset approximately 50% of patients are unable to walk unassisted(Polman and Uitdehaag, B. M. J., 2000, 321, 490-494).

MS takes several forms, with new symptoms either occurring in isolatedattacks (relapsing forms) or building up over time (progressive forms).

There is at present no known cure for multiple sclerosis. Currenttreatments attempt to improve function after an attack and/or preventsubsequent attacks.

Medications used to treat MS, while modestly effective, can have adverseeffects and be poorly tolerated.

There are a number of injectable front line therapies:

-   -   beta interferon 1a (Avonex)    -   beta interferon 1a (Rebif)    -   beta interferon 1b (Betaferon)    -   glatiramer acetate (Copaxone)

Interferons may produce flu-like symptoms and some people takingglatiramer experience a post-injection reaction with flushing, chesttightness, heart palpitations, breathlessness, and anxiety, whichusually lasts less than thirty minutes. More dangerous but much lesscommon is liver damage. Copaxone is associated with skin irritation atthe site of injection

Additional therapies include:

-   -   Natalizumab reduces the relapse rate more than first-line        agents; however, due to issues of adverse effects such as        progressive multifocal leukoencephalopathy it is a second-line        agent reserved for those who do not respond to other treatments        or with severe disease.    -   Fingolimod (Gilenya)—licensed in March 2011 for people with        rapidly evolving severe relapsing remitting MS (two or more        relapses a year), and as a second line treatment for people        whose MS remains active despite treatment with one of the beta        interferon drugs.    -   Dimethyl fumarate (Tecfidera) was licensed by the FDA in 2013        and is an oral first line therapy for adults with relapsing        remitting forms of MS.    -   Teriflunomide (Aubagio) was approved by the FDA in September        2012, is an orally available immunomodulatory drug for the        treatment of relapsing forms of MS    -   Mitoxantrone, whose use is limited by severe adverse effects,        systolic dysfunction, infertility, and acute myeloid leukemia is        a third-line option for those who do not respond to other        medications.

Corticosteroids (or steroids) are sometimes given for a few days, eitherin the form of tablets or by intravenous drip. While there is noevidence that steroids have any effect on the long-term course of thedisease, they can be effective at speeding up recovery from relapse.

No treatment has been shown to change the course of primary progressiveMS and as of 2011 only one medication, mitoxantrone, has been approvedfor secondary progressive MS. In this population, tentative evidencesupports mitoxantrone moderately slowing the progression of the diseaseand decreasing rates of relapse over two years.

There is ongoing research looking for more effective, convenient, andtolerable treatments for relapsing-remitting MS.

Monoclonal antibodies have raised high levels of interest. The CD52monoclonal antibody alemtuzumab, CD25 monoclonal antibody daclizumab andCD20 monoclonal antibodies such as rituximab, ocrelizumab and ofatumumabhave all shown some benefit and are under study as potential treatments.Their use has also been accompanied by the appearance of potentiallydangerous adverse effects, most importantly opportunistic infections.

Accordingly, there is a huge unmet medical need for the treatment of MS.

SUMMARY OF THE INVENTION

The present invention provides new medicaments for the treatment ofautoimmune conditions, particularly multiple sclerosis. One embodimentof the invention describes compounds of formula (I)

and pharmaceutically acceptable salts and solvates thereof wherein:R¹ is selected from H and CH₃R² is selected from H, C₄H₉ alkyl, C₆H₁₃ alkyl and C₃H₆-phenyl, saidPhenyl optionally substituted by OH or OCH₃,

X is O or S Y is C, N or S.

Preferably alkyl chains are straight chain.

In a preferred embodiment, R¹ is H

In a preferred embodiment R² is selected from C₄H₉ alkyl, C₆H₁₃ alkyland C₃H₆-phenyl.

In a particularly preferred embodiment R² is C₃H₆-phenyl

In a preferred embodiment X is O

In a preferred embodiment Y is C or N

In a particularly preferred embodiment Y is N

Particularly preferred are those compounds of formula (I) where:

X is O Y is N R¹ is H; and

R² is selected from C₄H₉ alkyl, C₆H₁₃ alkyl and C₃H₆-phenyl.

In a particularly preferred embodiment R² is C₃H₆-phenyl

Particularly preferred compounds of the invention include:

-   2-amino-5-((butylamino)methyl)-3,7-dihydro-4H-pyrrolo[2,3-d]pyrimidin-4-one-   N-((2-amino-4-oxo-4,7-dihydro-3H-pyrrolo[2,3-d]pyrimidin-5-yl)methyl)butan-1-aminium    chloride-   2-amino-5-((hexylamino)methyl)-3,7-dihydro-4H-pyrrolo[2,3-d]pyrimidin-4-one-   N-((2-amino-4-oxo-4,7-dihydro-3H-pyrrolo[2,3-d]pyrimidin-5-yl)methyl)hexan-1-aminium    chloride-   Queuine;    2-amino-5-((((1S,4S,5R)-4,5-dihydroxycyclopent-2-en-1-yl)amino)methyl)-3,7-dihydro-4H-pyrrolo[2,3-d]pyrimidin-4-one-   Queuine HCl    2-Amino-5-[[[(1S,4S,5R)-4,5-dihydroxy-2-cyclopenten-1-yl]amino]methyl]-1,7-dihydro-4H-pyrrolo[2,3-d]pyrimidin-4-one,    monohydrochloride-   Most preferred is/are:    2-amino-5-(((3-phenylpropyl)amino)methyl)-3,7-dihydro-4H-pyrrolo[2,3-d]pyrimidin-4-one-   N-((2-amino-4-oxo-4,7-dihydro-3H-pyrrolo[2,3-d]pyrimidin-5-yl)methyl)-3-phenylpropan-1-aminium    chloride;

Suitable salts include salts of acidic or basic groups present incompounds of formula (I). The compounds of formula (I) that are basic innature are capable of forming a wide variety of salts with variousinorganic and organic acids. The acids that may be used to preparepharmaceutically acceptable acid addition salts of such basic compoundsof formula 1 are those that form non-toxic acid addition salts. Suitablesalts include acetate, benzenesulfonate, benzoate, bicarbonate,bisulfate, bitartrate, borate, bromide, calcium edentate, camsylate,carbonate, chloride, clavulanate, citrate, dihydrochloride edentate,edisylate, estolate, esylate, ethylsuccinate, fumarate, gluceptate,gluconate, glutamate, glycollylarsanilate, hexylresorcinate,hydrabamine, hydrobromide, hydrochloride, iodide isothionate, lactate,lactobionate, laurate, malate, maleate, mandelate, mesylate,methylsulfate, mucate, napsylate, nitrate, oleate, oxalate, pamoate,palmitate, pantothenate, phosphate, diphosphate, polygalacturonate,salicylate, stearate, subacetate, succinate, tannate, tartrate,teoclate, tosylate and valerate salts.

Preferred salts include hydrochloride and aminium chloride.

The subject invention also includes isotopically-labelled compoundswhich are identical to those described, but for the substitution of anatom for a corresponding isotope. Examples of isotopes include isotopesof hydrogen such as deuterium and tritium; isotopes of carbon such as¹³C. Other examples are well known to those skilled in the art.

Where appropriate, compounds of the present invention include anycis/trans isomers.

The compounds of the present invention may be synthesised by a number ofsynthetic routes. Scheme 1 describes a conventional synthetic protocolfor the synthesis of compounds of formula (I) where X & Y are asdescribed herein.

Compounds of formula (III) may be prepared from compounds of formula(II) by process step (i) addition of a suitable amine protecting group.The term ‘PG’ is used to denote any suitable protecting group. Suitablegroups and conditions may be found in ‘Protective Groups in OrganicSynthesis’ by Theodora W. Greene, Peter G. M. Wuts, 4th Edition, 2006,ISBN: 978-0-471-69754-1 published by Wiley

Particularly favoured protecting groups are octyl alkyl amides, whichresult in lower levels of by-products and isomers in subsequent steps.Compounds of formula (IV) may be produced from compounds of formula(III) via process step (ii) which an electrophilic aromatic substitutionreaction occurs between compound (iii) and the iminium ion formed by thecondensation of dibenzylamine with formaldehyde under the standardconditions of the Mannich-type reaction. Compounds of formula (I) may beproduced by process step (iii) an amine exchange reaction followed bycleavage of the protecting group under acidic or basic conditions, orwith a nucleophile.

An alternative route is described in scheme 2:

Compounds of formula (VI) may be made by reacting compound of formula(V) with suitable amine protecting group under the conditions of processstep (i).

Compounds of formula (VII) may be synthesised by steps consisting of thereduction and hydrolysis (in either order) of compounds of formula (VI).

Compounds of formula (I) may be made by reacting compounds of formula(VII) under the conditions of process (v)—a reductive amination followedby removal of the protecting group. Suitable conditions are describedunder ‘General Procedure A’ in the experimental.

Compounds of formula (Ia) may also be synthesised as described in Scheme3.

Compounds of formula (VIII) in which the PG is acid labile are treatedunder acidic conditions of process step (vi) to remove the acid labileprotecting group and form acid addition salt of (I), described as (Ia)

The invention also provides novel therapies for the treatment ofdisease.

Without being bound by theory, it appears the compounds of the presentinvention operate via a new drug pathway. They exploit an enzyme complexmade of two proteins TGT (tRNA guanine transglycosylase) also known asqueuine tRNA-ribosyltransferase 1, and Qv1 (queuine tRNAtransglycosylase domain containing 1). The effect is to increase therelative populations of Treg cells and/or decrease populations of Teffcells. Treg cells are a part of the immune system that are intricatelyinvolved in the determination of self from non-self proteins i.e.protecting proteins of the self being attacked by the immune system(which is the cause of many autoimmune diseases). Further data todemonstrate the efficacy of the compounds is provided in theexperimental section.

The transfer RNA (tRNA) of rapidly proliferating cells is deficient(hypomodified) in queuine modification; examples include foetal liver,multiple tumour types and regenerating adult liver. By contrast, thetRNA of adult, fully differentiated cells contains high levels ofqueuine, which cannot be displaced once incorporated.

It could be expected that the tRNA of rapidly expanding immune cells (asoccurs in an autoimmune response) are likewise deficient in the queuinemodification. Incorporation of novel Queuine Insertase substratesselectively into the queuine-deficient tRNA of immune cells coulddisrupt proliferation and cytokine production thereby modulating theimmune response.

The present invention provides new medicaments for the treatment ofautoimmune diseases, particularly multiple sclerosis.

This invention also relates to compounds of Formula (I)

Wherein:

R¹ is selected from H and CH₃R² is selected from H, C₄H₉ alkyl, C₆H₁₃ alkyl,(1R,2S,5S)-5-methylcyclopent-3-ene-1,2-diol and C₃H₆-phenyl, said phenyloptionally substituted by OH or OCH₃,

X is O or S Y is C, N or S.

and pharmaceutically acceptable salts and solvates thereof, for use as amedicament.

In a preferred embodiment

R¹ is selected from H and CH₃R² is selected from H, C₄H₉ alkyl, C₆H₁₃ alkyl and C₃H₆-phenyl, saidphenyl optionally substituted by OH or OCH₃,

X is O or S Y is C, N or S.

The invention also provides for compounds of formula (I) for use in thetreatment of autoimmune conditions such as rheumatoid arthritis,ulcerative colitis, psoriasis, diabetes and inflammatory bowel disease,including crohn's disease; and as agents to suppress transplantrejection.

This invention also relates to compounds of formula (I) as describedabove for use in the treatment of multiple sclerosis.

The invention also relates to a method of treating multiple sclerosis ina mammal, particularly a human, comprising administering to said mammalan amount of a compound of formula (I) as defined above, or apharmaceutically acceptable salt or solvate thereof.

The term ‘treatment’ is intended to include curing, reversing,alleviating, palliative and prophylactic treatment of the condition.

The invention further relates to molecules of the invention incombination with other suitable agents, for use in the treatmentmultiple sclerosis.

Patients suffering from multiple sclerosis are commonly co-administeredadditional therapeutic agents. For patients suffering a severe attack,intravenous corticosteroids, such as methylprednisolone or techniquessuch as or plasmapheresis may be coadministered with any treatment.

The effects of nerve cell damage caused by multiple sclerosis result indiverse forms of damage to the patient. Nerve damage can lead to pain,difficulty with control of bladder and many other issues. For thisreason, additional medicaments are often prescribed patients withmultiple sclerosis to help treat the effects of MS damage. Suitableco-administrants would include:

For Bladder problems

-   -   botulinum toxin (Botox)    -   desmopressin (Desmospray, Desmotabs)    -   oxybutynin (Ditropan, Lyrinel)    -   tolterodine (Detrusitol)

For Depression

-   -   amitriptyline (Triptafen)    -   fluoxetine (Prozac)    -   imipramine (Tofranil)    -   paroxetine (Seroxat)

For Erectile dysfunction

-   -   alprostadil (Caverject, MUSE, Viridal Duo)    -   sildenafil citrate (Viagra)    -   tadalafil (Cialis)    -   vardenafil (Levitra)

For Fatigue

-   -   amantadine (Lysovir, Symmetrel)    -   modafinil (Provigil)

For Optic neuritis

-   -   steroids

For Pain

-   -   amitriptyline (Triptafen)    -   carbamazepine (Tegretol)    -   gabapentin (Neurontin)    -   ibuprofen    -   imipramine (Tofranil)    -   lamotrigine (Lamictal)    -   phenytoin (Epanutim)    -   pregabalin (Lyrica)

For Problems with walking

-   -   fampridine (Fampyra)

For Psuedobulbar affect

-   -   Nuedexta

For Spasticity and spasms

-   -   baclofen (Lioresal)    -   botulinum toxin (Botox)    -   carbamazepine (Tegretol)    -   clonazepam (Rivotril)    -   dantrolene (Dantrium)    -   diazepam (Valium)    -   gabapentin (Neurontin)    -   phenol    -   Tetrahydrocannabinol and cannabidiol (Sativex)    -   tizanidine (Zanaflex)

For Tremor

-   -   clonazepam (Rivotril)    -   thalamotomy

For Trigeminal neuralgia

-   -   carbamazepine (Tegretol)    -   gabapentin (Neurontin)    -   oxcarbazepine (Trileptal)    -   phenytoin (Epanutim)    -   pregabalin (Lyrica)

Other therapeutic agents are commonly administered to patients with MS.Other such medicaments are well known to physicians and others skilledin therapy.

Such agents may be administered sequentially, simultaneously orconcomitantly.

The invention also relates to a pharmaceutical composition comprising amolecule of the present invention and a pharmaceutically acceptablediluent or carrier.

Pharmaceutical compositions suitable for the delivery of compounds ofthe present invention and methods for their preparation will be readilyapparent to those skilled in the art. Such compositions and methods fortheir preparation may be found, for example, in Remington'sPharmaceutical Sciences, 19th Edition (Mack Publishing Company, 1995).

Compounds of formula (I) may be administered orally. Oral administrationmay involve swallowing, so that the compound enters the gastrointestinaltract, or buccal or sublingual administration may be employed by whichthe compound enters the blood stream directly from the mouth.Formulations suitable for oral administration include solid formulationssuch as tablets, capsules containing particulates, liquids, or powders,lozenges (including liquid-filled), chews, multi- and nano-particulates,gels, solid solution, liposome, films, ovules, sprays and liquidformulations.

Liquid formulations include suspensions, solutions, syrups and elixirs.Such formulations may be employed as fillers in soft or hard capsulesand typically comprise a carrier, for example, water, ethanol,polyethylene glycol, propylene glycol, methylcellulose, or a suitableoil, and one or more emulsifying agents and/or suspending agents. Liquidformulations may also be prepared by the reconstitution of a solid, forexample, from a sachet.

Compounds of formula (I) may also be used in fast-dissolving,fast-disintegrating dosage forms such as those described in ExpertOpinion in Therapeutic Patents, 11 (6), 981-986, by Liang and Chen(2001).

For tablet dosage forms, depending on dose, the drug may make up from 1weight % to 80 weight % of the dosage form, more typically from 5 weight% to 60 weight % of the dosage form. In addition to the drug, tabletsgenerally contain a disintegrant. Examples of disintegrants includesodium starch glycolate, sodium carboxymethyl cellulose, calciumcarboxymethyl cellulose, croscarmellose sodium, crospovidone,polyvinylpyrrolidone, methyl cellulose, microcrystalline cellulose,lower alkyl-substituted hydroxypropyl cellulose, starch, pregelatinisedstarch and sodium alginate. Generally, the disintegrant will comprisefrom 1 weight % to 25 weight %. In one embodiment of the presentinvention, the disintegrant will comprise from 5 weight % to 20 weight %of the dosage form. Binders are generally used to impart cohesivequalities to a tablet formulation. Suitable binders includemicrocrystalline cellulose, gelatin, sugars, polyethylene glycol,natural and synthetic gums, polyvinylpyrrolidone, pregelatinised starch,hydroxypropyl cellulose and hydroxypropyl methylcellulose. Tablets mayalso contain diluents, such as lactose (monohydrate, spray-driedmonohydrate, anhydrous and the like), mannitol, xylitol, dextrose,sucrose, sorbitol, microcrystalline cellulose, starch and dibasiccalcium phosphate dihydrate. Tablets may also optionally comprisesurface active agents, such as sodium lauryl sulfate and polysorbate 80,and glidants such as silicon dioxide and talc. When present, surfaceactive agents may comprise from 0.2 weight % to 5 weight % of thetablet, and glidants may comprise from 0.2 weight % to 1 weight % of thetablet. Tablets also generally contain lubricants such as magnesiumstearate, calcium stearate, zinc stearate, sodium stearyl fumarate, andmixtures of magnesium stearate with sodium lauryl sulphate. Lubricantsgenerally comprise from 0.25 weight % to 10 weight %. In one embodimentof the present invention, lubricants comprise from 0.5 weight % to 3weight % of the tablet. Other possible ingredients includeanti-oxidants, colourants, flavouring agents, preservatives andtaste-masking agents.

Exemplary tablets contain up to about 80% drug, from about 10 weight %to about 90 weight % binder, from about 0 weight % to about 85 weight %diluent, from about 2 weight % to about 10 weight % disintegrant, andfrom about 0.25 weight % to about 10 weight % lubricant.

Tablet blends may be compressed directly or by roller to form tablets.Tablet blends or portions of blends may alternatively be wet-, dry-, ormelt-granulated, melt congealed, or extruded before tabletting. Thefinal formulation may comprise one or more layers and may be coated oruncoated; it may even be encapsulated. Formulations of tablets arediscussed in Pharmaceutical Dosage Forms: Tablets, Vol. 1, by H.Lieberman and L. Lachman (Marcel Dekker, New York, 1980).

Consumable oral films for human or veterinary use are typically pliablewater-soluble or water-swellable thin film dosage forms which may berapidly dissolving or mucoadhesive and typically comprise a compound offormula (I), a film-forming polymer, a binder, a solvent, a humectant, aplasticiser, a stabiliser or emulsifier, a viscosity-modifying agent anda solvent. Some components of the formulation may perform more than onefunction. The film-forming polymer may be selected from naturalpolysaccharides, proteins, or synthetic hydrocolloids and is typicallypresent in the range 0.01 to 99 weight %, more typically in the range 30to 80 weight %. Other possible ingredients include anti-oxidants,colorants, flavourings and flavour enhancers, preservatives, salivarystimulating agents, cooling agents, co-solvents (including oils),emollients, bulking agents, anti-foaming agents, surfactants andtaste-masking agents. Films in accordance with the invention aretypically prepared by evaporative drying of thin aqueous films coatedonto a peelable backing support or paper. This may be done in a dryingoven or tunnel, typically a combined coater dryer, or by freeze-dryingor vacuuming.

Solid formulations for oral administration may be formulated to beimmediate and/or modified release. Modified release includes delayed,sustained, pulsed, controlled, targeted and programmed release. Suitablemodified release formulations for the purposes of the invention aredescribed in U.S. Pat. No. 6,106,864. Details of other suitable releasetechnologies such as high energy dispersions and osmotic and coatedparticles are to be found in Pharmaceutical Technology On-line, 25(2),1-14, by Verma et al (2001). The use of chewing gum to achievecontrolled release is described in WO-A-00/35298.

Compounds of formula (I) may also be administered directly into theblood stream, into muscle, or into an internal organ. Such parenteraladministration includes intravenous, intraarterial, intraperitoneal,intrathecal, intraventricular, intraurethral, intrasternal,intracranial, intramuscular and subcutaneous administration. Suitabledevices for parenteral administration include needle (includingmicroneedle) injectors, needle-free injectors and infusion techniques.

Compounds of the invention may also be administered topically to theskin or mucosa, that is, dermally or transdermally.

The compounds of formula (I) can also be administered intranasally or byinhalation, typically in the form of a dry powder (either alone, as amixture, for example, in a dry blend with lactose, or as a mixedcomponent particle, for example, mixed with phospholipids, such asphosphatidylcholine) from a dry powder inhaler, as an aerosol spray froma pressurised container, pump, spray, atomiser (preferably an atomiserusing electrohydrodynamics to produce a fine mist), or nebuliser, withor without the use of a suitable propellant, such as1,1,1,2-tetrafluoroethane or 1,1,1,2,3,3,3-heptafluoropropane, or asnasal drops. For intranasal use, the powder may comprise a bioadhesiveagent, for example, chitosan or cyclodextrin. For intranasal use, thepowder may comprise a bioadhesive agent, for example, chitosan orcyclodextrin

The pressurised container, pump, spray, atomizer, or nebuliser containsa solution or suspension of the compound of formula (I) comprising, forexample, ethanol, aqueous ethanol, or a suitable alternative agent fordispersing, solubilising, or extending release of the compound, apropellant as solvent and an optional surfactant, such as sorbitantrioleate, oleic acid, or an oligolactic acid.

Prior to use in a dry powder or suspension formulation, the drug productis micronised to a size suitable for delivery by inhalation (typicallyless than 5 microns). This may be achieved by any appropriatecomminuting method, such as spiral jet milling, fluid bed jet milling,supercritical fluid processing to form nanoparticles, high pressurehomogenisation, or spray drying.

Capsules (made, for example, from gelatin orhydroxypropylmethylcellulose), blisters and cartridges for use in aninhaler or insufflator may be formulated to contain a powder mix of thecompound of the invention, a suitable powder base such as lactose orstarch and a performance modifier such as I-leucine, mannitol, ormagnesium stearate. The lactose may be anhydrous or in the form of themonohydrate, preferably the latter. Other suitable excipients includedextran, glucose, maltose, sorbitol, xylitol, fructose, sucrose andtrehalose.

A suitable solution formulation for use in an atomiser usingelectrohydrodynamics to produce a fine mist may contain from 1 μg to 20mg of the compound of the invention per actuation and the actuationvolume may vary from 1 μl to 100 μl. A typical formulation may comprisea compound of formula (I) propylene glycol, sterile water, ethanol andsodium chloride. Alternative solvents which may be used instead ofpropylene glycol include glycerol and polyethylene glycol.

Suitable flavours, such as menthol and levomenthol, or sweeteners, suchas saccharin or saccharin sodium, may be added to those formulations ofthe invention intended for intranasal administration. Formulations forintranasal administration may be formulated to be immediate and/ormodified release using, for example, PGLA. Modified release includesdelayed, sustained, pulsed, controlled, targeted and programmed release.

Compounds of formula (I) may also be administered directly to the eye orear, typically in the form of drops of a micronised suspension orsolution in isotonic, pH-adjusted, sterile saline.

Compounds of formula (I) may be combined with soluble macromolecularentities, such as cyclodextrin and suitable derivatives thereof orpolyethylene glycol-containing polymers, in order to improve theirsolubility, dissolution rate, taste, bioavailability and/or stabilitywhen using any of the aforementioned modes of administration.Drug-cyclodextrin complexes, for example, are found to be generallyuseful for most dosage forms and administration routes. Both inclusionand non-inclusion complexes may be used. As an alternative to directcomplexation with the drug, the cyclodextrin may be used as an auxiliaryadditive, i.e. as a carrier, diluent, or solubiliser. Most commonly usedfor these purposes are alpha-, beta- and gamma-cyclodextrins, examplesof which may be found in international patent publicationsWO-A-91/11172, WO-A-94/02518 and WO-A-98/55148.

EXPERIMENTAL

The synthesis of various molecules suitable for use in the presentinvention are described below.

All starting materials and reagents are commercially available and wereobtained from Aldrich with exception of2-amino-3H-pyrrolo[2,3-d]pyrimidin-4(7H)-one which was purchased fromFluorochem.

Preparation 1: 2-octanoylamino-pyrrolo[2,3-d]pyrimidin-4-one

A 50 cm³ round-bottomed flask containing a stirring bar was charged with2-amino-3H-pyrrolo[2,3-d]pyrimidin-4(7H)-one (2.00 g, 13.33 mmol). Theflask was fitted with a septum and placed under an Ar atmosphere.Freshly distilled pyridine (20.00 cm³) was added via syringe and theresulting suspension cooled on ice. The solution was allowed toequilibrate at this temperature (ca. 5 min) and then octanoyl chloride(6.80 cm³, 39.99 mmol) was added dropwise. The resulting suspension washeated at 85° C. for 30 min. After cooling to room temperature 6.5%ethanolic ammonia (60 cm³) was added and the resulting suspensionstirred at room temperature overnight. The precipitate of product wasremoved via vacuum filtration and washed with ethanol followed bydiethyl ether to yield the desired product (2.56 g, 70%) pure as ayellow solid, m.p.>300° C. (decomposition). Procedure based on Akimotoet al. 1986 and Akimoto et al. 1988.

δ_(H) (400 MHz, DMSO-d₆): 0.86 (3H, t, J 5.1), 1.26 (8H, m), 1.58 (2H,app. quintet), 2.01 (1H, br s, NH), 2.43 (2H, t, J 5.1), 6.40 (1H, d, J2.0), 7.01 (1H, d, J 2.0), 11.43 (1H, br s, NH), 11.67 (1H, br s, NH)

HRMS (m/z ESI⁻). Found: 275.1517 ([M−H]⁻ C₁₄H₁₉N₄O₂; Requires: 275.1508)

Preparation 2:2-octanoylamino-5-((dibenzyl)amino)methyl)-pyrrolo[2,3-d]pyrimidin-4-one

A 50 cm³ reaction vessel containing a stirring bar was charged with2-octanoylamino-pyrrolo[2,3-d]pyrimidin-4-one (1.00 g, 3.60 mmol),dibenzylamine (2.00 cm³, 10.80 mmol), formalin (349.00 μL, 12.60 mmol)and 80% aqueous acetic acid (36 cm³). The resulting suspension washeated at 60° C. for 20 h, cooled to room temperature, diluted with 0.5M HCl (36 cm³) and stirred at room temperature for 30 min. The mixturewas neutralised with conc. aq. ammonia (36 cm³) and extracted withchloroform (3×50 cm³). The organic extracts were combined, dried (MgSO₄)and evaporated to dryness. The crude residue was purified by columnchromatography (9:1 dichloromethane-MeOH—7:3 dichloromethane-MeOH) togive the desired compound (1.45 g, 84%) as a yellow powder m.p.>300° C.(decomposition). Procedure based on Akimoto et al. 1986 and Akimoto etal. 1988.

δ_(H) (400 MHz, DMSO-d₆): 0.86 (3H, t, J 7.1), 1.25 (8H, m), 1.57 (2H,m) 2.42 (2H, t, J 7.1), 3.57 (4H, s), 3.76 (2H, s), 6.88 (1H, s), 7.23(2H, t, J 7.3), 7.31 (4H, app. t), 7.41 (4H, d, J 7.3), 11.34 (1H, s,NH), 11.57 (1H, s, NH), 11.68 (1H, s, NH)

HRMS (m/z ESI⁺). Found: 486.2863 ([M+H]⁺ C₂₉H₃₆N₅O₂; requires: 486.2869)

Example 1:2-amino-5-(((3-phenylpropyl)amino)methyl)pyrrolo[2,3-d]pyrimidin-4-one

A large carousel tube containing a stirring bar was charged with2-octanoylamino-5-((dibenzyl)amino)methyl)-pyrrolo[2,3-d]pyrimidin-4-one(100.0 mg, 0.21 mmol), 3-phenylpropylamine (146.00 μL, 1.03 mmol) and1:1 THF-methanol (2.00 cm³). The suspension was degassed and thereaction vessel sealed. The suspension was heated at 75° C. for 24 h,cooled to room temperature and treated with 5 M KOH (146.00 μL) andstirred at room temperature for 65 h. The solution was concentrated invacuo and the crude residue purified by column chromatography (9:0.9:0.1dichloromethane-MeOH—NH₄OH). The resulting solid was washed with HPLCgrade hexane followed by diethyl ether in order to remove traceimpurities. This gave the desired compound (28 mg, 46%) as an orangepowder, m.p.>300° C. (decomposition). Procedure based on Akimoto et al.1986 and Akimoto et al. 1988.

δ_(H) (600 MHz, DMSO-d₆): 1.24 (1H, br s, NH), 1.66 (2H, app. quintet),1.91 (1H, s, NH), 2.44 (2H, t, J 6.9), 2.57 (2H, t, J 6.9), 3.59 (2H,s), 6.15 (2H, br s), 6.45 (1H, s), 7.15 (1H, t, J 7.4), 7.16 (3H, m),7.25 (2H, app. t), 10.70 (1H, br s)

δ_(C) (600 MHz, DMSO-d₆): 30.6, 32.9, 45.2, 47.5, 48.6, 79.2, 98.7 (q),113.6 (q), 125.5, 128.2, 128.3, 142.3 (q), 152.2 (q), 160.5 (C═O)

ν_(max) (film)/cm⁻¹: 697, 748, 749, 1080, 1420, 1596, 2927

HRMS (m/z ESI⁺). Found: 298.1662 ([M+H]⁺ C₁₆H₂₀N₅O; Requires: 298.1668)

Preparation 3: 2-chloro-3-oxopropanenitrile

In a dry round bottomed flask under a positive pressure of argon, asuspension of NaOMe (7.14 g, 0.13 mol) in dry THF (90 mL) was cooled to−5° C. Methyl formate (9 mL, 0.15 mol) was added dropwise over 1 min bysyringe and stirring was continued at −5° C. for 20 min. Thenchloroacetonitrile (8.33 mL, 0.13 mol) was added dropwise via a droppingfunnel over 45 min. The mixture turned from white to yellow and wasstirred for a further 2 h at −5° C. at which point the reaction mixturewas orange. The bath was removed and the reaction was allowed to warm upto room temperature. An aliquot of the reaction mixture was treated witha drop of concentrated HCl and analysed by TLC which indicated thepresence of the desired product with an R_(f)=0.45, eluting with 100%EtOAc. The mixture was cooled to 0° C. and concentrated HCl (12 mL) wasadded dropwise during which time the mixture reaction became cherry-red.The resultant suspension was filtered through a pad of celite, and thecelite was washed with EtOAc until the filtrate became colourless. Thecollected filtrates were concentrated at reduced pressure with the waterbath at a temperature no higher than 40° C. to affordchloro(formyl)acetonitrile¹ as a black oil, in quantitative yield, whichwas used without further purification. Procedure based on Brooks 2012.

δ_(H) (400 MHz, CDCl₃) 9.38 (s, 1H).

δ_(C) NMR (400 MHz, DMSO-d₆) δ 168.2, 126.6, 67.8.

Preparation 4:2-amino-4,7-dihydro-4-oxo-3H-pyrrolo[2,3-d]pyrimidine-5-carbonitrile

2,4-Diamino-6-hydroxypyrimidine (3.00 g, 24 mmol) was added to asolution of sodium acetate (6.4 g, 76 mmol) in millipore water (90 mL)and stirred at 50° C. for 1 hour. While still at 50° C. a solution ofcrude chloro(formyl)acetonitrile (3.00 g, 32 mmol) in mQ water (44 mL)was added dropwise with a dropping funnel, during which time thereaction turned beige and heating continued for 18 h at 50° C., afterwhich time the reaction was heated to 100° C. for 3 h. The reactionmixture was allowed to cool to room temperature and the solid removed byfiltration. The solid was suspended in EtOH and 5M aqueous KOH solutionwas added until the solid dissolved. Charcoal was added to the solutionand the mixture stirred for 30 minutes before removal of the solid byfiltration. The pH of the filtrate was adjusted to pH=6 withconcentrated aqueous HCl solution during which time a precipitate formedand was collected by filtration. In order to remove the final traces ofwater from the solid it was dissolved in a mixture of toluene/methanol1/1 and then concentrated at reduced pressure. The resultant solid wasdried over P₂O₅ to afford the desired compound (1.68 g, 9.6 mmol, 40%yield) as beige solid. Procedure based on Brooks 2012.

δ_(H) (400 MHz, DMSO-d₆) δ 11.98 (br s, 1H) 10.74 (br s, 1H), 7.59 (s,1H), 6.43 (s, 2H).

δ_(C) (100 MHz, DMSO-d₆) δ 158.0, 154.3, 152.1, 128.2, 116.4, 99.2,86.0.

HRMS (m/z ESI⁻): C₇H₅N₅O [M−H]⁻ Found 174.0415 Requires: 174.0416.

Preparation 5:4,7-Dihydro-4-oxo-2-[(triphenylmethyl)amino]-3H-pyrrolo[2,3-d]pyrimidine-5-carbonitrile

In a dry round bottomed flask under an atmosphere of argon, tritylchloride (1.20 g, 4.28 mmol) was added to a solution of2-amino-4,7-dihydro-4-oxo-3H-pyrrolo[2,3-d]pyrimidine-5-carbonitrile(0.50 g, 2.85 mmol) in dry pyridine (29 mL). The mixture reaction washeated at 90° C. for 48 h. The reaction mixture was concentrated underreduced pressure then absorbed on silica gel and purified by flashchromatography on silica gel eluting with dichloromethane/MeOH with agradient starting at 2% of MeOH and rising to 10%. The desired compoundwas obtained as a brown solid (0.63 g, 1.5 mmol, 53% yield).

Procedure based on Ölgen 2008.

δ_(H) (400 MHz, DMSO-d₆) δ 11.80 (br s, 1H); 10.64 (br s, 1H), 7.56 (s,1H), 7.41 (s, 1H), 7.29-7.28 (m, 12H), 7.23-7.17 (m, 3H), 5.73 (s, 1H).

HRMS (m/z ESI⁺): C₂₆H₁₈N₅O [M−H]⁺ Found 416.1514 Requires: 416.1511.

Preparation 6:4,7-Dihydro-4-oxo-2-[(triphenylmethyl)amino]-3H-pyrrolo[2,3-d]pyrimidine-5-carboxaldehyde

HMDS (6 mmol, 1.3 mL) was added to a mixture of4,7-dihydro-4-oxo-2-[(triphenylmethyl)amino]-3H-pyrrolo[2,3-d]pyrimidine-5-carbonitrile(1.30 g, 3 mmol) with ammonium sulphate (397 mg, 0.3 mmol) in drytoluene (8 mL) in a round bottomed flask. A reflux condenser was fitted,and the flask was heated at reflux temperature overnight. The mixturewas cooled to room temperature and concentrated under reduced pressure.Under a positive pressure of argon, the crude reaction mixture wassolubilised in dry dichloromethane (8 mL) and cooled to −78° C. At thistemperature, DiBAL-H (4.5 mL, 1 M in dichloromethane, 4.5 mmol) wasadded dropwise. After 2 hours, analysis by TLC (EtOAc 100%) indicatedthat some starting material remained. So, a further 2 mL DiBAL-Hsolution was added dropwise. After 1 hour, the reaction was complete anda mixture of H₂O/AcOH (9/1, 3.5 mL) was added at −78° C. The reactionmixture was allowed to warm to room temperature slowly. A mixture ofEtOAc/H₂O (1/1, 300 mL) was added to the reaction mixture and stirringcontinued at room temperature for 2 hours. The layers were separated andthe organic layer was washed with brine and the aqueous layers wereextracted with EtOAc. The combined organic fractions were dried overMgSO₄, filtered and concentrated at reduced pressure. The crude reactionproduct was filtered through a pad of silica gel eluting with EtOAc toafford a yellow solid (1.01 g, 2.38 mmol, 76%). Procedure based onBrooks 2010 and Brooks 2012.

δ_(H) (400 MHz, DMSO-d₆) δ 11.82 (s, 1H), 10.63 (s, 1H), 9.99 (s, 1H),7.54 (s, 1H), 7.31-7.27 (m, 13H), 7.23-7.19 (m, 3H).

HRMS (m/z ESI⁻): C₂₆H₁₈N₄O₂ [M−H]⁻ Found 419.1508 Requires: 419.1508.

Preparation 7:5-((3-phenylpropylamino)methyl)-2-(tritylamino)-3H-pyrrolo[2,3-d]pyrimidin-4(7H)-one

General Procedure A:

To a suspension ofN-((4-oxo-2-(tritylamino)-4,7-dihydro-3H-pyrrolo[2,3-d]pyrimidin-5-yl)methyl)formamide(200.0 mg, 0.48 mmol) and sodium sulphate (5.0 mg) in methanol (5 cm³)under an argon atmosphere was added 3-phenylpropylamine (74.00 μL, 0.52mmol) and the resulting suspension stirred at room temperature for 2 h.Sodium borohydride (55.00 mg, 1.43 mmol) was then added and the reactionmixture stirred at room temperature for a further 1 h. Water (5 cm³) wasadded and the resulting suspension stirred for 10 min before beingextracted with dichloromethane (3×5 cm³). The combined organic layerswere dried (MgSO₄) and concentrated in vacuo to yield the crude productwhich was purified by flash chromatography (9:1 dichloromethane-MeOH) toyield the desired compound as a white solid (210 mg, 41.8%), m.p.>300°C. (decomposition). Procedure based on Brooks 2010 and Brooks 2012.

¹H (400 MHz, DMSO-d₆): 1.73 (2H, quintet, J 7.8), 2.56 (4H, m), 3.74(1H, s), 6.42 (1H, s, H-6), 7.19 (20H, m), 7.45 (1H, bs, NH), 10.78 (1H,bs, NH)

¹³C (400 MHz, DMSO-d₆): 31.7, 32.8, 45.4, 47.8, 70.4 (q), 99.7 (q),114.9, 117.6 (q), 125.9, 126.0, 126.9, 128.0, 128.6, 129.0, 142.6 (q),145.4 (q), 150.0 (q), 150.4 (q), 159.7 (C═O)

HRMS (m/z −ESI⁺). Found: 540.2757 [M+H]⁺ C₃₅H₃₄N₅O Requires: 540.2765)

v_(max)/cm⁻¹: 1542, 1611, 1670, 2868, 2951

Example 2:N-((2-amino-4-oxo-4,7-dihydro-3H-pyrrolo[2,3-d]pyrimidin-5-yl)methyl)-3-phenylpropan-1-aminiumchloride

General Procedure B:

A 5 cm³ reaction vessel containing a stirring bar was charged with5-((3-phenylpropylamino)methyl)-2-(tritylamino)-3H-pyrrolo[2,3-d]pyrimidin-4(7H)-one(210.0 mg, 0.39 mmol) and 1.25 M methanolic HCl (3 cm³). The resultingsolution was stirred at room temperature for 16 h. The precipitatedproduct was removed by vacuum filtration and washed with dichloromethaneto yield the desired compound as a white powder (84 mg, 68%), m.p.>300°C. (decomposition). Procedure based on Brooks 2010 and Brooks 2012.

δ_(H) (600 MHz, DMSO-d₆): 1.90 (2H, app. quintet), 2.63 (2H, t, J 7.8),2.90 (2H, m), 4.13 (2H, t, J 5.2), 6.57 (2H, bs), 6.80 (1H, d, J 2.3),7.16 (3H, m), 7.26 (2H, t, J 7.0), 9.11 (2H, bs), 11.05 (1H, m, NH),11.31 (1H, broad doublet, NH).

δ_(C) (125 MHz, DMSO-d₆): 27.6, 32.1, 42.9, 45.6, 48.9, 98.6, 108.7 (q),117.9 (q), 126.4, 128.6, 128.7, 140.9 (q), 152.9 (q), 160.5 (C═O)

HRMS (m/z ESI⁺). Found: 298.1662 (M⁺ C₁₆H₂₀N₅O Requires: 298.1664)

ν_(max) (film)/cm⁻¹: 1456, 1625, 2443, 2713, 2756, 2873, 2933, 3184

Preparation 85-((3-butylamino)methyl)-2-(tritylamino)-3H-pyrrolo[2,3-d]pyrimidin-4(7H)-one

Prepared as per general procedure A usingN-((4-oxo-2-(tritylamino)-4,7-dihydro-3H-pyrrolo[2,3-d]pyrimidin-5-yl)methyl)formamide(200.00 mg, 0.48 mmol), n-butylamine (95.00 μL, 0.95 mmol) and NaBH₄ (55mg, 1.43 mmol) to yield the desired product as a white powder (200 mg,88%), m.p.>300° C. (decomposition).

δ_(H) (400 MHz, DMSO-d₆): 0.84 (3H, t, J 7.3), 1.30 (2H, app. sextet),1.51 (2H, app. quintet), 2.82 (2H, t, J 7.3), 4.01 (2H, s), 6.62 (1H,s), 7.24 (15H, m), 7.57 (1H, bs), 11.07 (1H, bs)

δ_(C) (400 MHz, DMSO-d₆): 13.9, 19.6, 28.0, 42.9, 46.0, 70.6 (q), 99.4(q), 108.9, 118.0 (q), 127.0, 128.1, 129.0, 145.2 (q), 150.5 (q), 150.6(q), 160.3 (C═O)

ν_(max) (film)/cm⁻¹: 1545, 1613, 1672, 2870, 2956

HRMS (m/z ESI⁺). Found: 478.2600 ([M+H]+C₃₀H₃₂N₅O; Requires: 478.2607)

Example 3N-((2-amino-4-oxo-4,7-dihydro-3H-pyrrolo[2,3-d]pyrimidin-5-yl)methyl)butan-1-aminiumchloride

Prepared as per general procedure B using5-((butylamino)methyl)-2-(tritylamino)-3H-pyrrolo[2,3-d]pyrimidin-4(7H)-one(108 mg, 0.39 mmol) and 1.25 M methanolic HCl (3 cm³) to yield thedesired product as a white powder (72 mg, 67%), m.p.>300° C.(decomposition).

δ_(H) (400 MHz, DMSO-d₆): 0.86 (3H, t, J 7.4), 1.31 (2H, app. sextet),1.57 (2H, app. quintet), 2.90 (2H, m), 4.12 (2H, t, J 5.3), 6.49 (2H,bs), 6.81 (1H, s), 9.01 (2H, bs), 10.98 (2H, bs), 11.29 (1H, bs)

δ_(C) (400 MHz, DMSO-d₆): 18.7, 24.7, 32.7, 47.4, 50.6, 103.6 (q),114.0, 123.2 (q), 153.3 (q), 157.6 (q), 164.7 (C═O)

HRMS (m/z ESI⁺). Found: 236.1518 (M⁺ C₁₁H₁₈N₅O Requires: 236.1511)

ν_(max) (film)/cm⁻¹: 1456, 1625, 1668, 2443, 2713, 2756, 2873, 2933,3184

Preparation 95-((3-hexylamino)methyl)-2-(tritylamino)-3H-pyrrolo[2,3-d]pyrimidin-4(7H)-one

Prepared as per general procedure A usingN-((4-oxo-2-(tritylamino)-4,7-dihydro-3H-pyrrolo[2,3-d]pyrimidin-5-yl)methyl)formamide(200.0 mg, 0.48 mmol), n-hexylamine (125.00 μL, 0.95 mmol) and sodiumborohydride (55 mg, 1.43 mmol) to yield the desired product as a whitepowder (200 mg, 83.0%), m.p.>300° C. (decomposition).

δ_(H) (400 MHz, DMSO-d₆): 0.82 (3H, t, J 7.4), 1.20 (6H, m), 1.34 (2H,app. quintet), 2.40 (2H, t, J 7.4), 3.60 (2H, s), 6.30 (1H, s), 7.23(15H, m), 7.37 (1H, bs), 10.62 (1H, bs)

δ_(C) (400 MHz, DMSO-d₆): 14.4, 22.5, 26.8, 31.6, 29.6, 45.2, 48.3, 70.4(q), 99.7 (q), 115.2, 116.7 (q), 127.0, 128.1, 129.0, 145.4 (q), 150.1(q), 150.5 (q), 159.7 (C═O)

ν_(max) (film)/cm⁻¹: 1552, 1648, 1734, 2856, 2928

HRMS (m/z ESI⁻). Found: 504.2769 ([M−H]⁻ C₃₂H₃₄N₅O; Requires: 504.2763)

Example 4N-((2-amino-4-oxo-4,7-dihydro-3H-pyrrolo[2,3-d]pyrimidin-5-yl)methyl)hexan-1-aminiumchloride

Prepared as per general procedure B using5-((hexylamino)methyl)-2-(tritylamino)-3H-pyrrolo[2,3-d]pyrimidin-4(7H)-one(190 mg, 0.39 mmol) and 1.25 M methanolic HCl (3 cm³) to yield thedesired product as a white powder (70 mg, 64.8%), m.p.>300° C.

δ_(H) (400 MHz, DMSO-d₆): 0.83 (3H, t, J 7.2), 1.25 (6H, m), 1.59 (2H,app. sextet, J 7.2), 2.87 (2H, m), 4.11 (2H, t, J 5.3), 6.71 (2H, bs),6.84 (1H, d, J 3.6), 9.11 (2H, bs), 11.25 (1H, bs), 11.46 (1H, bs)

δ_(C) (400 MHz, DMSO-d₆): 14.3, 22.3, 25.8, 25.9, 31.1, 42.6, 46.1, 98.9(q), 109.3 (q), 118.5, 148.1 (q), 152.8 (q), 159.8 (C═O)

ν_(max) (film)/cm⁻¹: 1578, 1625, 1669, 2429, 2712, 2861, 2930, 2957,3266.

HRMS (m/z ESI⁺). Found: 264.1830 ([M+H]⁺ C₁₃H₂₂N₅O Requires: 264.1824)

-   H. Akimoto et al., J. Chem. Soc. Perkin Trans 1, 1998, 1627-1644.-   H. Akimoto et al., J. Med. Chem., 1986, 29, 1749-1753.-   S. Ölgen et al., Arch. Pharm. Chem. Life Sci., 2008, 341, 113-120.-   A. F. Brooks et al., Tetrahedron Lett., 2010, 51, 4163-4165.-   A. F. Brooks PhD Thesis “Synthesis of Tritium Labeled Queuine, PreQ1    and Related Azide Probes Toward Examining the Prevalence of Queuine”    University of Michigan, 2012.

To assess the potential of these compounds in vivo, a chronic monophasicEAE disease in mice was induced before treatment with the new chemicalentity (NCE). EAE Disease was induced in 8-10 week old female mice(C57BL/6) by sub-cutaneous (s.c.) injection of 200 μl emulsioncontaining 150 μg MOG₃₃₋₅₅ peptide (Genscript) in Complete Freund'sAdjuvant (CFA; containing 5 mg/ml heat-inactivated Mycobacteriumtuberculosis). On the same day, mice were administered 500 ng PertussisToxin (Kaketsuken, Japan) intraperitoneally (i.p.) and again two dayslater. Disease severity was recorded every 24 hours: 0-Normal; 1-flaccidtail; 2-impaired/wobbly gait; 3-complete hind limb weakness; 4-hind limband forelimb paralysis; 5-moribund state/dead. Protocol is based on theNature Protocols for Active induction of experimental allergicencephalomyelitis, which includes the scoring methodology:

-   Stromnes I M, Goverman J M (2006) Active induction of experimental    allergic encephalomyelitis. Nat Protoc. 1(4):1810-9.

FIG. 1 shows the results of the in vivo testing for moleculeN-((2-amino-4-oxo-4,7-dihydro-3H-pyrrolo[2,3-d]pyrimidin-5-yl)methyl)-3-phenylpropan-1-aminiumchloride (Compound I). The EAE score relates to an assessment of diseaseprogression with respect to issues like tail paralysis and limbparalysis, a higher score is a worse condition. A score of 1 indicatesdecreased tail tone, a score of 2 indicates hind leg weakness(paraparesis), a score of 3 indicates hind limb paralysis and/orincontinence. Note that the untreated animals have a continuous andprogressive worsening of disease. In contrast, the animals treated withN-((2-amino-4-oxo-4,7-dihydro-3H-pyrrolo[2,3-d]pyrimidin-5-yl)methyl)-3-phenylpropan-1-aminiumchloride (Compound I) exhibit rapid (within 24 hrs) reversal of symptomsat the highest dosage given (30 mg/kg, i.p.) and animals were scored asdisease free after 4 daily treatments. At lower doses animals wereslower to respond but in all cases disease progression was halted andreversed.

FIG. 2 shows that in agreement with the observed disability scores,treated animals showed a dramatic return to normal weight gain, reachinga weight level 96.6% that of controls (19.9 grams versus 20.6 grams), at21 days post inoculation (dpi). This contrasts with the sustained dropin body weight of non-treated EAE diseased animals to a level 86.4% thatof controls at 21 dpi (17.8 grams versus 20.6 grams). Motor coordinationand hind-limb strength were also evaluated by the ability of mice tocross a horizontal bar (FIG. 3). Non-diseased animals crossed the barwith an average time of 4.3±0.57 seconds. From 9 dpi, EAE mice showed arapid deterioration in performance and were subsequently unable tomaintain a grip on the apparatus. Strikingly,N-((2-amino-4-oxo-4,7-dihydro-3H-pyrrolo[2,3-d]pyrimidin-5-yl)methyl)-3-phenylpropan-1-aminiumchloride (Compound I) treatment fully restored the performance of EAEdiseased mice to control levels within 4 treatments.

1. A compound of formula (I)

Or pharmaceutically acceptable salt thereof Wherein: R¹ is selected fromH and CH₃ R² is selected from H, C₄H₉ alkyl, C₆H₁₃ alkyl, andC₃H₆-phenyl, said phenyl optionally substituted by OH or OCH₃ X is O orS; and Y is C, N or S.
 2. The compound of Formula (I) of claim 1,wherein X is O.
 3. The compound of Formula (I) of claim 1, wherein Y isC or N.
 4. The compound of Formula (I) of claim 1, wherein Y is N. 5.The compound of Formula (I) of claim 1, wherein R¹ is H.
 6. The compoundof Formula (I) of claim 1, wherein R² is selected from the groupconsisting of C₄H₉ alkyl, C₆H₁₃ alkyl, and C₃H₆-phenyl.
 7. The compoundof Formula (I) of claim 1, wherein R² is C₃H₆-phenyl.
 8. The compound ofFormula (I) of claim 1, wherein X is O; Y is N; R¹ is H; and R² isselected from the group consisting of C₄H₉ alkyl, C₆H₁₃ alkyl, andC₃H₆-phenyl.
 9. The compound of Formula (I) of claim 8, wherein R² isC₃H₆-phenyl.
 10. A medicament comprising compounds of formula (I)

Wherein: R¹ is selected from H and CH₃; R² is selected from H, C₄H₉alkyl, C₆H₁₃ alkyl, (1R,2S,5S)-5-methylcyclopent-3-ene-1,2-diol, andC₃H₆-phenyl, said phenyl optionally substituted by OH or OCH₃, X is O orS Y is C, N or S; and pharmaceutically acceptable salts and solvatesthereof.
 11. The medicament of claim 10, wherein R¹ is selected from Hand CH₃, R² is selected from H, C₄H₉ alkyl, C₆H₁₃ alkyl and C₃H₆-phenyl,said phenyl optionally substituted by OH or OCH₃, X is O or S, Y is C, Nor S, and pharmaceutically acceptable salts and solvates thereof. 12.The medicament of claim 10, wherein the medicament is adapted fortreatment of autoimmune diseases.
 13. The medicament of claim 12,wherein the autoimmune disease is multiple sclerosis.
 14. A method oftreating autoimmune diseases in a mammal comprising administering tosaid mammal an amount of a compound of formula (I)

wherein: R¹ is selected from H and CH₃, R² is selected From H, C₄H₉alkyl, C₆H₁₃ alkyl, (1R,2S,5S)-5-methylcyclopent-3-ene-1,2-diol, andC₃H₆-phenyl, said phenyl optionally substituted by OH or OCH₃, X is O orS, Y is C, N or S, and pharmaceutically acceptable salts and solvatesthereof.
 15. The medicament of claim 10, further comprising anadditional therapeutic agent.
 16. The medicament of claim 13, furthercomprising an additional therapeutic agent.
 17. The medicament of claim10, further comprising a pharmaceutically acceptable carrier ordiluents.